Aquarium



FIG. 1 is a front elevational view of an aquarium showing my new design; the rear elevational view being a mirror image thereof;

FIG. 2 is a side view, taken from the left side of FIG. 1;

FIG. 3 is a side view, taken from the right side of FIG. 1;

FIG. 4 is a top plan view thereof; and,

FIG. 5 is a bottom plan view thereof. 

The ornamental design for an aquarium, as shown and described. 